Guidance on this issue is provided in both a Defence Council Instruction (DCI) and a Defence Operational Instruction (DOI) on the retention of captured enemy equipment as operational memorabilia (OM).
Specifically in relation to OM: the DCI states
“Units are to ensure that neither items of private property nor those that could be seen as having historical, cultural or religious significance are removed.”
and the DOI states
“Items of private property or items that could be seen as having historic, cultural or religious significance are not to be removed.”
In addition there are provisions within the agreements between UK and the host nation in which our troops are serving that state that personnel will respect the laws, regulations, customs and traditions of the host country insofar as this is compatible with the entrusted task and mandate.